US11879572B2ActiveUtilityA1

Tube fitting and tube equipped with tube fitting

79
Assignee: SANOH IND CO LTDPriority: Feb 22, 2019Filed: Feb 19, 2020Granted: Jan 23, 2024
Est. expiryFeb 22, 2039(~12.6 yrs left)· nominal 20-yr term from priority
Inventors:Takahiro GunjiAtsushi Kurosawa
F16L 19/025B32B 1/08B60T 17/043F16L 19/0243F16L 19/0283F16L 58/04F16L 58/184B32B 2597/00F16L 19/0206B05D 7/24B05D 5/00B05C 11/1005B05D 2507/01F16L 19/0286
79
PatentIndex Score
1
Cited by
29
References
20
Claims

Abstract

A tube fitting is provided with a resin coating layer over a coated region surfaces of a threaded portion and a contact portion. The resin coating layer includes a polyethylene based substance, a lubricant, and solid particles. When mass per unit area w (g/m 2 ) is defined as a value obtained by dividing the mass difference between a state with the resin coating layer and a state without the resin coating layer by the surface area of the coated region, the mass per unit area w satisfies a relation 0.79<w<10.07.

Claims

exact text as granted — not AI-modified
The invention claimed is: 
     
       1. A tube fitting that is capable of coupling a tube made from metal and provided with an annular portion upon an end portion thereof, to a mating member by being installed upon an external periphery of the tube and by being fastened to the mating member in a state of contacting the annular portion, the annular portion projecting in a radially outward direction from the tube,
 the tube fitting comprising: 
 a threaded portion upon which is formed an external thread that engages with an internal thread provided in the mating member; 
 a contact portion that is provided at an end portion of the tube fitting in a direction of progression of the external thread when the tube fitting is being fastened, and that, when the tube fitting is fastened to the mating member, contacts the annular portion to press the annular portion against the mating member; and 
 a resin coating layer provided over a coated region that includes surfaces of the threaded portion and the contact portion; 
 and wherein: 
 a through hole extending in a direction parallel to the direction of progression is pierced through both the threaded portion and the contact portion; 
 the external thread has an outer diameter of 9.53 to 14.0 mm, and the contact portion has an inner diameter of 4.98 to 8.44 mm; 
 the resin coating layer includes a polyethylene based substance, a lubricant, and solid particles; a thickness of the resin coating layer is not uniform throughout the coated region; 
 and when mass per unit area w (g/m 2 ) is defined as being a value obtained by dividing a mass difference between a state with the resin coating layer and a state without the resin coating layer by a surface area of the coated region, 
 the mass per unit area w satisfies a relation 0.79<w<10.07. 
 
     
     
       2. The tube fitting according to  claim 1 , wherein the mass per unit area w satisfies a relation 1.20<w<10.07. 
     
     
       3. The tube fitting according to  claim 1 , wherein the mass per unit area w satisfies a relation 0.79<w<9.00. 
     
     
       4. The tube fitting according to  claim 1 , wherein the mass per unit area w satisfies a relation 0.79<w<7.50. 
     
     
       5. The tube fitting according to  claim 1 , wherein the mass per unit area w satisfies a relation 0.79<w<6.00. 
     
     
       6. The tube fitting according to  claim 1 , wherein, when a testing member corresponding to the mating member and a testing tube having a same outer diameter as the tube and having a testing annular portion corresponding to the annular portion are prepared, and
 when a fastening test is repeated n times (where 1<n<6), the fastening test including: fastening operation to fasten the tube fitting to the testing member with a predetermined tightening torque, in a state that the contact portion is contacted against the testing annular portion; and release operation to release coupling of the testing tube from the testing member by loosening a fastening state after the fastening operation, 
 if a maximum axial force generated in a first performance of the fastening test is termed an initial axial force F 1  (kN) and a maximum axial force generated in an n-th performance of the fastening test is termed an n-th axial force F n  (kN), and if a value obtained by −(F n −F 1 )/(n−1) is defined as being an axial force decrease ratio α (kN/turn), then the axial force decrease ratio α satisfies a relation 0<α<1.75. 
 
     
     
       7. The tube fitting according to  claim 6 , wherein the tube is a brake tube that is employed as a brake conduit for an automobile, and, when the predetermined tightening torque is in a range of 12.0 to 22.0 Nm, the initial axial force F 1  satisfies a relation F 1 <14.0. 
     
     
       8. The tube fitting according to  claim 1 , wherein:
 a zinc based plated layer is formed upon the surfaces of the threaded portion and the contact portion respectively, and the resin coating layer is provided over the zinc based plated layer; and 
 a frictional coefficient of the resin coating layer is smaller than a frictional coefficient of the surfaces formed by the zinc based plated layer. 
 
     
     
       9. The tube fitting according to  claim 8 , wherein a zinc-nickel alloy plated layer is provided as the zinc based plated layer. 
     
     
       10. The tube fitting according to  claim 1 , wherein
 the resin coating layer is made by adhering coating material including the polyethylene based substance, the lubricant, and the solid particles to the coated region, and 
 a viscosity of the coating material is in a range of 4.24 to 5.27 mPa·s at a temperature of 25° C. measured using a rotational viscosimeter having a spindle and conforming to the ISO 2555:1990 standard, a rotational speed of the spindle being set to 60 rpm. 
 
     
     
       11. The tube fitting according to  claim 1 , wherein:
 the tube is provided with a bent portion at a position remote from the annular portion; 
 the tube fitting that is installed upon the external periphery of the tube so as to be prevented from coming off by the annular portion and the bent portion; and 
 the resin coating layer includes a polyethylene based substance, a lubricant, and solid particles. 
 
     
     
       12. The tube fitting according to  claim 11 , wherein the mass per unit area w satisfies a relation 1.20<w<10.07. 
     
     
       13. The tube fitting according to  claim 11 , wherein the mass per unit area w satisfies a relation 0.79<w<9.00. 
     
     
       14. The tube fitting according to  claim 11 , wherein the mass per unit area w satisfies a relation 0.79<w<7.50. 
     
     
       15. The tube fitting according to  claim 11 , wherein the mass per unit area w satisfies a relation 0.79<w<6.00. 
     
     
       16. The tube fitting according to  claim 11 , wherein:
 the tube is a brake tube that is employed as a brake conduit for an automobile; and 
 when a testing member corresponding to the mating member and a testing tube having a same outer diameter as the tube and having a testing annular portion corresponding to the annular portion are prepared, and when a fastening test is repeated n times (where 1<n<6), the fastening test including: tightening operation to fasten the tube fitting to the testing member with a tightening torque in the range of 12.0 to 22.0 Nm, in a state that the contact portion is contacted against the testing annular portion; and release operation to release coupling of the testing tube from the testing member by loosening a fastening state after the tightening operation, 
 if a maximum axial force generated in a first performance of the fastening test is termed an initial axial force F 1  (kN) and a maximum axial force generated in an n-th performance of the fastening test is termed an n-th axial force F n  (kN), and if a value obtained by −(F n −F 1 )/(n−1) is defined as being an axial force decrease ratio α (kN/turn), 
 then the initial axial force F 1  satisfies a relation F 1 <14.0 and the axial force decrease ratio α satisfies 0<α<1.75. 
 
     
     
       17. The tube fitting according to  claim 12 , wherein:
 the tube is a brake tube that is employed as a brake conduit for an automobile; and 
 when a testing member corresponding to the mating member and a testing tube having a same outer diameter as the tube and having a testing annular portion corresponding to the annular portion are prepared, and when a fastening test is repeated n times (where 1<n<6), the fastening test including: tightening operation to fasten the tube fitting to the testing member with a tightening torque in the range of 12.0 to 22.0 Nm, in a state that the contact portion is contacted against the testing annular portion; and release operation to release coupling of the testing tube from the testing member by loosening a fastening state after the tightening operation, 
 if a maximum axial force generated in a first performance of the fastening test is termed an initial axial force F 1  (kN) and a maximum axial force generated in an n-th performance of the fastening test is termed an n-th axial force F n  (kN), and if a value obtained by −(F n −F 1 )/(n−1) is defined as being an axial force decrease ratio α (kN/turn), then the initial axial force F 1  satisfies a relation F 1 <14.0 and the axial force decrease ratio α satisfies 0<α<1.75. 
 
     
     
       18. The tube equipped with a tube fitting according to  claim 16 , wherein:
 a zinc based plated layer is formed upon the surfaces of the threaded portion and the contact portion respectively; 
 the resin coating layer is provided over the zinc based plated layer; 
 a zinc-nickel alloy plated layer is provided as the zinc based plated layer; and 
 a frictional coefficient of the resin coating layer is smaller than a frictional coefficient of the surfaces formed by the zinc based plated layer. 
 
     
     
       19. The tube fitting according to  claim 1 , wherein:
 the tube is a brake tube that is employed as a brake conduit for an automobile; 
 when a testing member corresponding to the mating member and a testing tube having a same outer diameter as the tube and having a testing annular portion corresponding to the annular portion are prepared, and a fastening test is repeated n times (where 1<n<6), the fastening test including: fastening operation to fasten the tube fitting to the testing member with a tightening torque in a range of 12.0 to 22.0 Nm, in a state that the contact portion is contacted against the testing annular portion; and release operation to release coupling of the testing tube from the testing member by loosening a fastening state after the fastening operation, 
 if a maximum axial force generated in a first performance of the fastening test is termed an initial axial force F 1  (kN) and a maximum axial force generated in an n-th performance of the fastening test is termed an n-th axial force F n  (kN), and if a value obtained by −(F n −F 1 )/(n−1) is defined as being an axial force decrease ratio α (kN/turn), 
 a range of the mass per unit area w is set so as to satisfy relations: F 1 <14.0 and 0<α<1.75. 
 
     
     
       20. The tube fitting according to  claim 19 , wherein a range of the mass per unit area w is 1.20<w<10.07.

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